WHY YOUR CAR SHAKES WHEN IDLING If your car feels smooth while driving but starts vibrating or shaking at a stoplight, something isn't right. At idle, the engine runs at its WHY SOME ENGINES IDLE ROUGHER THAN OTHERS Some cars idle like a sewing machine others shake, pulse, and sound angry even when standing still. That difference is all about engine WHY YOUR CAR SHAKES WHEN IDLING If your car feels smooth while driving but starts vibrating or shaking at a stoplight, something isn't right. At idle, the engine runs at its Car Shaking at Idle: 8 Causes and When to See a Mechanic (2026 Guide)